package com.util;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

public class QRCodeUtil {
    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;


    public static BufferedImage createQRCode(String content,int width, int height) throws Exception {
        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        Map hints = new HashMap();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        BitMatrix bitMatrix;
        bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE,
                width, height, hints);
        return toBufferedImage(bitMatrix);
    }

    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }

    public static void writeToFile(String content,int width, int height, String format, File file)
            throws Exception {
        BufferedImage image = createQRCode(content, width, height);;
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format "
                    + format + " to " + file);
        }
    }

    public static void writeToStream(String content,int width, int height, String format,
                                     OutputStream stream) throws Exception {
        BufferedImage image = createQRCode(content, width, height);
        if (!ImageIO.write(image, format, stream)) {
            throw new Exception("Could not write an image of format " + format);
        }
    }
}
